Borescopic optical system for medical diagnostic instruments and medical diagnostic instruments having interlocking assembly features

ABSTRACT

A medical diagnostic instrument or a plurality of disparate medical diagnostic instruments are configured with a common optical architecture that functionally creates a virtual eye to create closer proximity to a patient and therefore increase the field of view in regard to a target of interest. The optical system includes a distal optical element, at least one relay lens and an eyepiece lens in which the optical system can be integrated within at least one instrument or be provided using a releasable module. Additionally, at least one of a viewing assembly and illumination assembly of at least one medical diagnostic instrument can be assembled using a series of components that are connected by interlocking features.

CROSS REFERENCE TO RELATED APPLICATION

This application is based on U.S. Patent Application Ser. No.62/071,128, entitled Borescopic Optical System for Medical DiagnosticInstruments and Medical Diagnostic Instruments Having InterlockingAssembly Features, filed Sep. 15, 2014, pursuant to relevant portions of35 U.S.C. §111 and 37 CFR §1.53, the entire contents of which is hereinincorporated by reference.

TECHNICAL FIELD

This application relates generally to the field of diagnostic medicineand more specifically to a medical diagnostic instrument having anenhanced field of view, as well as an optical architecture that can becommonly shared by a suite of disparate diagnostic instruments.

BACKGROUND

Certain instruments are well known in the medical field for conductingphysical assessments of patients and in which separate instruments areused for examining specific target areas. For example, ophthalmoscopesare used by a primary physician or ophthalmologist for examining theeyes, otoscopes are utilized for examining the ear canal and tympanicmembrane, and laryngoscopes are used for examining the throat passage.

A general pervasive issue with these physical assessment devices is inproviding a suitably large field of view of the intended target ofinterest. For example, it is desirable and advantageous to be able toaccess the entire tympanic membrane while using an otoscope. It isfurther desirable to be able to capture more of the retinal area of theeye all at once during an examination.

An issue in creating a larger field of view is that of the instrumentitself. For example and with ophthalmoscopes, the field of view can beexpanded by shortening the working distance between the patient and theinstrument. The foregoing, however, creates issues in terms of anxietyand discomfort for the patient. It is therefore desirable to provide amedical diagnostic instrument that can provide a larger field of view,but without having to shorten the working distance between theinstrument and the patient.

Yet another pervasive issue in the field relates to improvingmanufacturability of such diagnostic instruments in order to reducelabor and associated material costs by using a minimum number ofcomponents, but without sacrificing reliability. To better deal withthis concern, it would be extremely beneficial to develop a suitableoptical architecture that could be shared between multiple types ofphysical assessment devices and to develop a simpler manufacturingmethod for these devices.

BRIEF DESCRIPTION

According to one aspect, there is provided a medical diagnosticinstrument configured for viewing a target of interest, the instrumentcomprising an instrument housing having a distal end, an opposingproximal end and an interior. An optical system that is disposed withinthe interior of the instrument housing comprises a distal objectivelens, at least one intermediately disposed relay lens and a proximaleyepiece lens. Each of the lenses are commonly disposed along an opticalaxis, in which the optical system is configured to create an entrancepupil distal of the distal end of the instrument in order to create anincreased field of view of the target of interest. According to at leastone embodiment, the instrument is an ophthalmoscope.

In a preferred version, the herein described optical system creates anentrance pupil that is distal of the instrument housing. This entrancepupil establishes a “virtual eye” of the caregiver that increases theworking distance and the field of view by effectively shifting the eyeof the caregiver away from the patient's eye. The optical elements usedfor purpose of this system can be defined by a plastic molded design inwhich each of the optical elements are reversible/symmetrical andcorrected for optical aberrations by means of aspheric curves. Accordingto at least one embodiment, each of the lenses include a raisedperipheral edge to protect the lenses from surface damage. At least onefield stop can be provided for minimizing glare or unwanted light fromthe system.

The optical system can be disposed within a viewing assembly thatincludes features that enable interlocking connection with theillumination assembly.

In at least one embodiment, the optical system can be integrated as partof the instrument. In one version, a module equipped with the aboveoptical system can be releasably attached to the medical diagnosticinstrument to create the entrance pupil and also thereby increase thefield of view.

According to yet another aspect, an otoscope is provided that comprisesan instrument head having a distal end opening, an opposing proximal endopening and a substantially hollow interior enabling a target ofinterest to be viewed by a caregiver in a first mode. A module isreleasably attachable for insertion into the interior of the instrumenthead, the module having an optical system that increases the field ofview for viewing a target of interest in a second mode.

According to at least embodiment, the module comprises a distal opticalelement, at least one intermediate relay lens element and a proximaleyepiece lens element, each of the lens elements being aligned with thedistal and proximal end openings of the instrument head when attached.The instrument head can include a proximal window that is releasablyremovable to permit inclusion of the module.

In at least one embodiment, each of the lens elements of the module aremade from a molded plastic, wherein each of the lens elements of themodule are symmetric and reversible. In at least one version, each ofthe lens elements in the optical system are interchangeable. Accordingto at least one embodiment, each of the lens elements can furtherinclude a raised peripheral edge along each optical surface thereof tominimize damage during handling and assembly.

The at least one relay lens and eyepiece lens element can be axiallydisposed in relation to at least one flexible member within a modulehousing, the module further including a twistable retaining cap that canpermit minor positional adjustments of the lens elements to effect minorfocus adjustments.

According to another aspect, a plurality of medical diagnosticinstruments are provided wherein each of the medical diagnosticinstruments include an optical system that is configured to produce avirtual pupil at the distal end of the instrument in order to increasethe field of view. The plurality of instruments may include an otoscopeand an ophthalmoscope, among others.

In one embodiment, the optical system can be integrated within at leastone instrument housing. In another version, a module having the opticalsystem can be releasably attached to at least one of the medicaldiagnostic instruments.

The optical system can include an objective distal lens, at least oneintermediate relay lens and a proximal eyepiece lens, each of the lensesbeing commonly disposed along an optical axis of the instrument. In oneversion, each of the lenses of the optical system comprise symmetricreversible optical surfaces. In a preferred version, the lenses can bemade from a moldable plastic in which each side of the lens can includea raised peripheral edge that can act in order to minimize damage to theoptical surfaces during handling thereof in assembly.

In at least one embodiment, at least one of the medical diagnosticinstruments further comprises an illumination assembly and in which theoptical system and the illumination assembly can include features toenable an interlocking connection therebetween. In at least one version,the illumination assembly can include a plurality of components havingrespective features to enable interlocking connection therebetween.

The instruments having the common optical system can includeophthalmoscopes and otoscopes, among others. The optical system caninclude at least one distal optical element and at least one pair ofrelay lenses commonly disposed along an optical axis of the instrumentand wherein the optical system is configured to create an entrance pupilthat is distal of the distal end of the instrument housing in order tocreate the expanded field of view.

According to yet another aspect, a method is provided for manufacturinga medical diagnostic instrument to increase the effective field of viewof the instrument. The method comprises providing an optical system inthe instrument, the optical system having at least a distal objectivelens, at least one intermediate relay lens and a proximal eyepiece lensin which the optical system is configured to create an entrance pupildistal of a distal end of the instrument.

In one version, each of the lenses of the optical system can besymmetric and reversible. According to one embodiment, the lenses caninclude a raised peripheral edge along each optical surface that canminimize damage while handling during assembly. In one version, thelenses can be made from plastic.

The medical diagnostic instrument can be at least one of anophthalmoscope and an otoscope. According to one version, the opticalsystem is provided as a module to an existing medical diagnosticinstrument, such as an otoscope, the method further including the stepof providing the module for inclusion into the interior of theinstrument following removing of a releasable proximal window of theinstrument. As such, the otoscope can then be configured to operate inseparate modes depending on the inclusion of the releasably attachablemodule; namely, a first mode that enables the inclusion of tools withinthe interior of the otoscope, and a second enhanced field of view modethat includes the module.

According to yet another aspect, there is provided an optical module forplacement within a medical diagnostic instrument to increase theeffective field of view with respect to a target of interest, the modulecomprising a module housing including at least one distal opticalelement and at least one pair of relay lenses disposed within aninterior of the housing and aligned commonly along an optical axis andwherein the optical system forms an entrance pupil distal of the distalend of the module to create an entrance pupil.

According to yet another aspect, there is provided a physical assessmentdevice comprising an instrument housing having an interior, a viewingassembly disposed between distal and proximal end openings of theinstrument housing, and an illumination assembly including at least onelight source for illuminating a target of interest. According to thisaspect, at least one of the viewing assembly and illumination assemblycan have a plurality of components that are assembled by means ofinterlocking engagement. According to at least one embodiment, theillumination assembly and viewing assembly can include interlockingfeatures that enable releasable connection therebetween.

According to one version, the illumination assembly can be configuredfor interlocking connection with a first viewing assembly having a firstfield of view and a second viewing assembly having a second field ofview in which one of the viewing assemblies produces a distal entrancepupil for providing an enhanced field of view of an intended target ofinterest. In one version, the viewing assembly can be provided with aborescopic optical system comprising a distal objective lens, at leastone intermediate relay lens, and a proximal eyepiece lens. Theinstrument can, for example, be an ophthalmoscope.

In one embodiment, each of the lenses used in the optical system aresymmetrical and reversible, enabling the lenses to be easily assembledand without creating manufacturing errors. To further prevent damage tooptical surfaces, the lenses can include a raised peripheral edge oneach optical surface.

One advantage realized herein is that of modularization which canprovide a common optical architecture for a number of disparate medicaldiagnostic instruments.

Another advantage is that the optical adapter when attached to a medicalinstrument, such as an otoscope, can further permit access of anintended target by tools, as needed.

Yet another advantage is that an enhanced field of view as provided bythe herein described optical system permits more reliable andcomprehensive examinations of a patient to be conducted.

Still another advantage realized is that of faster diagnostic patientexaminations in that the realized enhanced field of view permits easiernavigation by the caregiver of a larger target area in order to find theintended point of interest and to pan the instrument.

Additionally and through the virtual pupil that is created, the targetof interest is actually made closer which provides more magnification,thereby making it considerably easier for the caregiver to discernfeatures of the intended medical target.

These and other features and advantages will be readily apparent fromthe following Detailed Description, which should be read in conjunctionwith the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1(a) is a side perspective view of a prior art medical diagnosticinstrument and more specifically, an otoscope;

FIG. 1(b) is a rear perspective view of the prior art otoscope of FIG.1(a);

FIG. 2(a) is a front view of another prior art medical diagnosticinstrument and more specifically, an ophthalmoscope;

FIG. 2(b) is a side elevational view of the ophthalmoscope of FIG. 2(a);

FIG. 3 is a perspective view of a medical diagnostic instrument made inaccordance with an embodiment;

FIGS. 4(a)-4(g) are partial assembly views, shown in sequence, of themedical diagnostic instrument of FIG. 3;

FIG. 5 is a simplified perspective view of a modular version of anoptical system for releasable attachment to a medical diagnosticinstrument and in accordance with another embodiment;

FIG. 6 is a partially assembled side elevational view of a medicaldiagnostic instrument made in accordance with another embodiment;

FIGS. 7(a)-7(k) depicts sequential partial assembly views of a portionof the medical diagnostic instrument of FIG. 6;

FIGS. 8(a)-(f) depict sequential partial assembly views of an opticalassembly for a medical diagnostic instrument made in accordance with anembodiment, including a sectioned view of an optical system which isshown in FIG. 8(c);

FIGS. 9(a)-(c) depict partial views of a medical diagnostic instrumentmade in accordance with yet another embodiment;

FIGS. 10(a) and 10(b) are perspective views of the assembled medicaldiagnostic instrument of FIGS. 9(a)-9(c);

FIG. 11 is a side elevational view, shown in section, of a medicaldiagnostic instrument in accordance with yet another embodiment;

FIG. 12 is a optical layout comparing a prior art otoscope with anotoscope having an optical system in accordance with an embodiment;

FIG. 13 is an optical layout comparing a prior art ophthalmoscope withan ophthalmoscope configured in accordance with an embodiment; and

FIG. 14 is a schematic depiction comparing a prior direct ophthalmoscopewith an instrument configured with an optical system in accordance withan embodiment.

DETAILED DESCRIPTION

The following relates to various embodiments of physical assessmentdevices or instruments as well as components that are engageabletherewith, each of which can be configured with a common opticalarchitecture that permits an enhanced field of view of a medical targetof interest. More specifically, the description relates to embodimentsthat are directed to optical otoscopes and ophthalmoscopes. It will bereadily understood that the concepts discussed herein may be applicableto other physical assessment devices, including versions of digitallyconfigured devices employing electronic imagers or devices. In additionand throughout this description, several terms are often used in orderto provide a suitable frame of reference with regard to the accompanyingdrawings. These terms, which include “exterior”, “interior”, “distal”,“proximal”, “inner”, “outer” and the like are not intended to limit thescope of the concepts which are discussed and claimed herein, except inthose instances where so specifically indicated.

For purposes of background and referring to FIGS. 1(a) and 1(b), atypically known otoscope 100 is defined by an instrument head 104 havinga distal end 108 and an opposing proximal end 112, which further definesa hollow interior 115. An axisymmetric speculum tip element (not shown)can be releasably attached, typically by means of a bayonet-typeconnection, in overlaying relation onto a truncated frusto-conicalinsertion portion 124 disposed at the distal end 108 of the instrumenthead 104. The distal insertion portion 124 includes a slot 126 forreleasably engaging an interior feature of the speculum tip element, aswell as a distal opening 128 that is aligned with the distal opening ofthe speculum tip element. When attached to the instrument 100 and inuse, the speculum tip element is configured to be placed up to apredetermined distance into the ear canal of a patient.

The caregiver observes the ear canal through a magnifying optic orwindow 130 that is provided at the proximal end 112 of the instrumenthead 104. The instrument head 104 is supported by a handle (not shown)that includes at least one rechargeable battery configured toelectrically power a contained light source, typically an incandescentor halogen bulb, that is disposed at an upper end of the instrumenthandle. A lower portion of the instrument head 104 includes a contactdisposed in a bayonet connector 132. A polished proximal end of thebundle of optical fibers (not shown) is optically coupled to the lightsource with the opposing ends encircling the interior of the distal endof the insertion portion 124 to create uniform illumination. Anadjustment control, such as a rheostat (not shown), is further providedin order to control the level of illumination. In use, this instrument100 is configured to have a field of view of approximately 15 degrees,while the diameter of the average tympanic membrane is approximately 7mm. Details relating to the design and operation of this medicaldiagnostic instrument, including the attachment to the handle areprovided in U.S. Pat. Nos. 3,698,387 and 3,978,850, the entire contentsof which are herein incorporated by reference.

With reference to FIGS. 2(a) and 2(b), a known optical ophthalmoscope200 typically includes an instrument head 204 that includes a distal end205 and an opposing proximal end 207, the instrument head 204 beingsupported to and connected through a bayonet connector 214 to aninstrument handle (not shown) that contains at least one rechargeablebattery connected to a light source provided in the upper end of thehandle. As in the case of the otoscope 100, FIG. 1, one polished end ofa bundle of optical fibers are optically coupled to the contained lightsource and the opposing end of the fiber bundle encircles the interiorof a distal opening of the instrument head 204 in order to directillumination toward the target of interest (eye). A diopter wheel 220 isdisposed for rotational movement relative to an optical axis of theinstrument 200, in which the caregiver can view portions of the eyethrough an aligned opening 232, 236 provided in the proximal and distalends 207, 205 of the instrument 200, as well as an aperture wheel 226.The instrument 200 further includes a sliding polarizer red/free switch228 beneath the opening 232.

Moving the instrument 200 closer to the patient will increase the fieldof view, but patients are made anxious when the instrument 200 isbrought into immediate proximity with the eye, and as a result theseinstruments 200 are typically used at an appropriate working distance(approximately 13-15 mm) between the patient and the instrument with theinstrument having a field of view of approximately 5 degrees. Detailsrelating to the workings, design and operation of this instrument areknown found in U.S. Pat. No. 4,526,449, the entire contents of which areherein incorporated by reference.

A medical diagnostic instrument made in accordance with a firstexemplary embodiment is provided in FIGS. 3-4(g). More specifically, theinstrument 400 is an otoscope having an instrument head 404 defined byrespective distal and proximal ends 406, 408. An illumination connector411 extends from the bottom of the instrument head 404, which ismechanically and electrically connected to the upper end of aninstrument handle (not shown). The instrument head 404 includes a cover428 having an insufflation port 409, as well as an attachment andretention mechanism 413 for releasably securing a speculum tip (notshown) in overlaying fashion onto a substantially conical distalinsertion portion 416, the latter mechanism including a rotatableactuator knob 419 disposed in relation to the insertion portion 416.

Though not shown, the illuminator connector 411 is configured to engagethe upper end of the instrument handle, using a bayonet-type connectionand in which the instrument handle is configured to retain at least onebattery (not shown), such as a rechargeable battery. A light source (notshown) such as an incandescent lamp or bulb is further provided at theupper end of the instrument handle in relation to a bundle of opticalfibers. The proximal ends of the optical fiber bundle are polished andoptically coupled with the light source. The optical fiber bundleextends into the instrument head 404 and encircle the interior diameterof a distal opening 406 of the conical distal insertion portion 416. Thedistal insertion portion 416 is shaped and configured to releasablyretain an axisymmetric speculum tip, the latter being configured forinsertion to a predetermined distance into the ear canal. The actuatorknob 419 of the tip attachment and retention mechanism 413 is configuredto engage and/or disengage with corresponding features on the speculumtip based on relative rotation between the speculum tip and the actuatorknob 419. Details relating to the tip attachment and retention mechanism413 and related aspects of the speculum tip and distal insertion portion416 are provided, for example, in U.S. Pat. No. 7,399,275, the entirecontents of which are herein incorporated by reference.

The following description details an assembly flow or process for theotoscope 400. First and as shown in FIG. 4(a), the herein describedotoscope 400 is shown with various components in an exploded viewincluding the illumination connector 411, the distal insertion portion416, an inner former 420, an optics assembly 430, and a portion of theouter cover 428. The inner former 420 is a structural portion of theinstrument 400 that includes a lower section 423 configured to receivesthe optical fiber bundle (not shown) extending upwardly from the lightsource (not shown) contained within the instrument handle (not shown)for purposes of illumination, similar to that described in regard to theinstrument 100 of FIG. 1 as well as an opening 427 that is sized toreceive the optics assembly 430. The tip attachment and retentionmechanism 413 is not shown in these assembly views for reasons ofclarity.

As shown in FIGS. 4(b) and 4(c), the optics assembly 430 is configuredto be fitted within the opening 427 of the inner former 420 with theouter cover 428 being further disposed about the exterior of the opticsassembly 430, as shown in FIG. 4(d), and the illumination connector 411being secured to the bottom of the assemblage, as shown in FIG. 4(e). Acutaway version of the assembled otoscope 400 is shown in FIG. 4(e)without a portion of the outer cover 428 for purposes of clarity. Asshown in FIG. 4(e) and when assembled, the proximal end of the opticsassembly 430 is roughly coplanar with the proximal end of the instrumenthead (i.e., cover 428).

The components of the herein described optics assembly 430 are shown inan exploded view in FIG. 4(f). According to this exemplary embodiment,the optics assembly 430 is defined by a housing 432 having a threeseparate diametrical sections; namely, a distal section 434, anintermediate section 435, and a proximal section 437. According to thisembodiment, the distal section is defined by an extended lengthterminating at the intermediate section 435, the latter having a largerinterior diameter than the distal section 434 and the proximal section437 having a larger diameter than that of the intermediate and distalsections 434, 435. Overall, the housing 432 is defined by a cylindricalconfiguration having tapered axial sections between the distal andintermediate sections 434 and 435 and between the intermediate section435 and the proximal section 437 of the housing 432.

The housing 432 is essentially hollow and is further defined byrespective distal and proximal end openings 439, 441 in which thehousing 432 is further configured to support a plurality of opticalcomponents. A plano window 444 is disposed at the distal end 439 of thehousing 432 in the distal section 434 with an objective lens 447 beingproximally disposed adjacent a plano window 444. According to thisexemplary embodiment, the objective lens 447 is made from an opticalgrade plastic, although alternatively, other materials that have opticalquality can be substituted. Referring to FIGS. 4(f) and 4(g), a relaylens 449 is further disposed within the intermediate section 435 of thehousing 432, with a field stop 451 being disposed between the relay lens449 and the objective lens 447.

Still referring to FIGS. 4(f) and 4(g), a first spacer 453 is proximallydisposed relative to the relay lens 449. The first spacer 453 is definedby a substantially cylindrical configuration having a distal portion 454that extends into the intermediate section 435 of the housing 432, aproximal section 456 that is disposed within the proximal section 435 ofthe housing 432 and an intermediate portion 458 having a tapercorresponding to the taper formed between the intermediate and proximalsections 435, 437 of the housing 432. The first spacer 453 issubstantially hollow, other than being configured with an interiornarrowed aperture 459 which is intended to block stray light, the firstspacer 453 and aperture 459 being centrally aligned with an optical axisof the assembly 430. A pair of O-rings 461 are disposed between thefirst spacer 453 and a proximally disposed second spacer 463, wherein afield stop 465 is disposed at the distal end of the second spacer 463.When assembled, the second spacer 463 is disposed within the proximalsection 437 of the housing 432 and includes a series of exteriorperipheral grooves 467 at the proximal end thereof that are sized andconfigured to retain at least one O-ring 469. An eyepiece lens 471 isretained at the proximal end of the second spacer 463. A retaining cap473 is configured to engage the exterior of the third section 437 of thehousing 432 in which the retaining cap 473 is defined by a cylindricalconfiguration having an open distal end 475 as well as a set ofengagement features, including annular slots 477, configured to engagecorresponding exterior features 479 provided on the exterior of theproximal portion 437 of the housing 432 when the retaining cap 473 isattached thereupon and twisted or rotated in a first direction.

The retaining cap 473 is further configured to retain a plano window 480that is sandwiched between a rear or proximal wall of the retaining cap473 and the proximal end of the housing 432, including the eyepiece lens471, wherein the rear wall of the retaining cap 473 further includes aproximal viewing opening 481.

As assembled, the plano windows 443, 480 at the distal and proximal endsof the housing 432 provide an effective seal relative to the interior ofthe optics assembly 430. Other than the relative sizes of the lenses447, 449 and 471, each of the lenses used herein according to thisexemplary embodiment are symmetric, meaning that both the distal andproximal facing sides are defined by the same curvature, which accordingto the present embodiment is a biconvex design. In addition, each of thelenses 447, 449, 471 according to this exemplary embodiment are madefrom an optical grade plastic, although any or all of the lenses couldalso be made from glass or other suitable material of optical quality.At the time of assembly, the engagement of the O-ring 469 as well as theO-rings 461 between the first and second spacers 453 and 469 can createa spring force when engaged by the retaining cap 473, when twisted, thatenables slight focus adjustments to be made to the herein describedoptics assembly 430.

When assembled, the distal end of the optics assembly 430 extends intothe interior of the conical insertion portion 416 and is substantiallyaligned with the distal opening 406 thereof. With reference to theoptical trace diagram provided at FIG. 11, illumination from a containedlight source in the instrument handle (not shown) can be directedthrough the distal opening 406 of the instrument head 404 in a mannerthat is known and in which an enhanced (larger) field of view ascompared to prior otoscopes, such as previously described according toFIG. 1, is produced. More specifically, the herein described opticsassembly 430 creates an entrance pupil 483 that is distal to the distalopening 406 of the otoscope 400 in which the contained objective lens447, relay lens 449 and eyepiece lens 471 create a upright image of thetarget of interest through imaging plane 482. The field stop 451 isprovided to reduce the effects of glare while the field stop 465 narrowsthe light relative to the eyepiece lens 471, creating a borescopicoptical train that effectively shifts the location of the caregiver'spupil to the entrance pupil 483, thereby creating an expansive field ofview.

Referring to FIG. 5 and shown schematically, an alternative instrumentversion can be contemplated in which an optical module 540, similar tothe herein described optical assembly 430, can be releasably disposedwithin the interior of an otoscope, such as the prior art version 100,FIG. 1, in lieu of providing an optical assembly that is alreadyintegrated within the instrument. According to this version, the module540 can have a similar configuration to that of the optics assembly ofthe previously described instrument, the module 540 being defined by atapering housing 544 that includes a distal end opening 546 and aopposing proximal end opening 548 that are axially aligned along adefined optical axis with the distal and proximal ends of the instrumenthousing. As in the preceding version, the contained optics produce avirtual pupil equivalent to that of the caregiver's eye which is createddistally relative to the distal end of the instrument with the lightbeing directed through a contained relay lens system to the caregiver'seye.

At least one additional pair of relay lenses could be provided in tandemalong the herein described optical axis of the instrument, depending onthe application/use of the instrument.

A medical diagnostic instrument made in accordance with anotherexemplary embodiment is herein described with reference to FIGS. 6-8(f).The instrument 600 described in accordance with this embodiment is anophthalmoscope, partially shown without a cover and instrument handle inFIG. 6, which is configured to function similarly to that previouslydescribed with reference to FIG. 2. The herein described versionincludes an illumination assembly 610, having a plurality of components,as well as a viewing or optical assembly 710.

First referring to FIGS. 7(a)-7(k), the assembly flow of an illuminationassembly 610 is herein described. As discussed herein, the majorcomponents of the illumination assembly 610 can be constructed using aset of interlocking components, facilitating the process of manufacture.At an initial point of assembly and referring to FIG. 7(a), a firstseries of components are assembled including an LED 612, such as a whiteLED, that is disposed onto a upper facing surface of a circuit board614. A spacer 616 used in the subassembly includes a defined throughaperture 618, as well as a lower flange 620 that is sized to retain anO-ring 622. A curved light pipe 624, made from a light conductingplastic, can be assembled with a portion 627 of light pipe beingretained within a slot 625 formed in the bottom surface 626 of thespacer 616 and in which the light pipe 624 includes an external notch631 that enables the O-ring 622 to secure the light pipe 624 in apredetermined position. Referring to FIGS. 7(c) and 7(d), the spacer 616can be fitted within a defined recess 629, FIG. 7(c), that is formed ina lower portion 630 of an assembly support member 628 relative to anaperture 634 that retains a lens element 636, which according to thisembodiment is an objective lens. A slot 638 is provided in the lowerportion 630 of the assembly support member 628 adjacent the recess 629that permits the retained light pipe 624 to extend outwardly from theassembly 610, as shown in FIG. 7(d).

In terms of assembly flow and prior to assembling the spacer 616, theobjective lens 636 is placed into the aperture 634 defined in the lowerportion 630 of the assembly support member 628. The assembly supportmember 628 according to this embodiment includes the lower portion 630,as well as an upper portion 637 and an intermediate portion 639. Thelower portion 630 of the assembly support member 628 is recessed with abottom surface having the recess 629 being disposed between a pair ofprojecting leg portions 642 that are configured and spaced in order toreceive an illumination connector 650 as well as the LED 612 and circuitboard 614.

Referring to FIG. 7(e), the assembly support member 628 and morespecifically the lower portion 630 thereof, is configured to receive theilluminator connector 650, shown partially exploded in FIG. 7(f). Theilluminator connector 650 according to this exemplary embodiment isdefined by an upper portion 654, a necked intermediate section 656, anda lower section 658, the latter section being defined with abayonet-type connector. The connector 650 is defined by a through axialcenter opening 660 defined by a first diameter extending into theintermediate necked portion 656 and a narrower diameter extending intothe lower portion 658, which is essentially hollow. A hollow insulator664 is installed within the center axial opening 660 of the upperportion 654 of the illuminator connector 650 with a lower portion 667 ofthe insulator 664 being sized to extend partially into the lower portion658. A center conductor 670 made from an electrically conductivematerial is similarly fitted within the confines of the hollow insulator664. When installed, and as shown in the assembled condition of FIG.7(e), an axial contacting end 673 of the center connector 670 extendsoutwardly from the insulator 664, with the end of the insulator 664being substantially flush with the top surface of the illuminatorconnector 650, as shown in FIG. 7(e).

Referring to FIGS. 7(e), (f) and (g), the upper portion 654 of theilluminator connector 650 is shaped and configured to releasably engagethe lower portion 630 of the assembly support member 628, as shown inFIG. 7(g) in an interlocking manner. More specifically and according tothis exemplary embodiment, the upper portion 654 is defined by a pair ofdiametrically opposed curved portions 677 and a pair of flats 678 thatare spaced to fit between the extending leg portions 642 of the lowerportion 630. The curved portions 677 extend above the plane of the topsurface of the illuminator connector 650 to provide ample spacing forthe LED 612 and circuit board 614 which is sandwiched therebetween suchthat the axial contacting end 673 of the center connector 670 can bebrought into contact with the circuit board 614. When assembledaccording to this configuration, the LED 612 and circuit board 614 areretained between the spacer 616 and more specifically, the O-ring 622and the center conductor 670 of the illumination connector 650 with thecurved portions 677 of the illuminator connector 650 being aligned withcorresponding curved portions 679 formed at the bottom of the lowerportion 630 of the assembly support member 628. A conductive spring clip682 can be used to secure the assembly support member 628 with theilluminator connector 650 by placement of same over the aligned curvedportions 677, following assembly in the position shown in FIG. 7(g).

Referring to FIG. 7(h), and following attachment of the assembly supportmember 628 to the illumination connector 650, a reticle wheel assembly686 can be attached to the intermediate portion of the assembly supportmember 628. According to this embodiment, the reticle wheel assembly 686includes an upper engagement portion 688, a lower engagement portion 690and an aperture wheel 692 that is supported for rotation and disposedbetween the upper and lower engagement portions 688, 690. The reticlewheel assembly 686 is fitted within a defined recess 644 formed in theintermediate section 639 of the assembly support member 628. Morespecifically, respective upper and lower surfaces defining the recess644 each include engagement rails 646 that are configured to engagesidewalls of the upper and lower engagement portions 688, 690 of thereticle wheel assembly 686 with the reticle wheel assembly 686 beingsized to fit in an interlocking manner with the assembly support member628. When assembled, a through aperture 696, including a reticle, isaligned with the LED 612, FIG. 4(a), and the lens element along anillumination axis of the assembly 610, as well as a through aperture 698in the upper section 637 of the assembly support member 628, as shown inFIG. 7(i).

As shown in FIGS. 7(i) and 7(j), a reticle lens 700 is then placed intothe through aperture 698. As shown in FIG. 7(k), a prismatic member 704is then attached to the upper portion 637 of the herein describedassembly member 628 and more specifically within a receiving cavity 706that is formed at the top of the upper portion 637 of the assemblysupport member 628 and in alignment with the through aperture 698. Theprismatic member 704 according to this embodiment includes an angledreflective surface 707. Alternatively, a mirror could be disposed toprovide similar functionality. The design of the prismatic member can besuitably varied, such as shown by prismatic member 704A in FIG. 11.

As discussed, each of the components of the herein describedillumination assembly 610 can be assembled according to this embodimentin an interlocking fashion without requiring fasteners such as screws,bolts or rivets. That is, each of the components of the foregoingassembly 610 can be built onto one another in a sequential fashion, suchas described with reference to FIGS. 7(a)-7(k). The components can bemade, for example, from a durable plastic.

Referring to FIG. 8(a), an optical assembly 710 in accordance with anexemplary embodiment is disposed in relation to the herein describedillumination assembly 610 prior to assembly therewith. Additionaldetails regarding the optical assembly 710 are herein discussed withreference to FIGS. 8(b) and 8(c) in which the herein described assemblyincludes a housing 712 made up of an lower or bottom section 716 and anupper or top section 720. The lower section 716 is defined a top surface724 having a semicircular groove 728 defined therein in which a firstlens 732 is provided at one end of the groove 728 and a second lens 736is defined at the opposing end of the groove 728. A pair of ears 730extend upwardly from opposing sides of the lower section 716 relative tothe second lens 736, the ears 730 including a vertical portion 734 and atransverse portion 738 extending from the top of the vertical portion734 in substantially the same direction as the defined groove 728, butoutwardly relative to the top surface 724. A plurality of posts 742extend upwardly from the top surface 724 on opposing sides of thesemicircular groove 728.

The upper section 720 of the housing 712 according to this embodimentincludes a first portion 750 that is sized to cover the lower section716, the interior surface (not shown) of this section 720 including asemicircular groove (not shown) that is aligned with the groove 728provided on the lower section 716 and forming an optical tube withrespect to the first and second lenses 732, 736. The first portion 750is sized to be fitted between the ears 730 of the lower section 716wherein the spaced ears 730 are sized to extend above the upper section720 of the housing 712. A second adjacent portion 754 of the top section720 includes a raised surface 756 that, when assembled, is substantiallyparallel to the top surface 724 of the lower section 716 but directlybeneath and between the transverse ear portions 738, this surface 756including a center slot or opening 760 that is sized to receive a detent764.

A third adjoining section 766 of the housing 712 is defined by a tubularsection 770 that is aligned with the semicircular groove of the firstsection 750. A plurality of components are disposed within the tubularsection 770, which combines to form an optical system with the two lenselements 732, 736 provided in the semicircular groove 728 formed in thetop surface 724 of the lower section 716. It will be understood,however, that this two-part design is exemplary and that othervariations and modifications are possible.

Still referring to FIGS. 8 (b) and (c), the components disposed withinthe tubular section 770 of the housing include a relay lens 776 that ispositioned within the distal end of a lens carrier 780 having a throughaperture. The lens carrier 780 is essentially hollow and for conveniencecan be built as a two-part assembly to enable assembly of the relay lens776. The lens carrier 780 is defined by a substantially cylindricalsection having a first diameter that is sized to support the relay lens776 and a second diameter that is retained against a shoulder formed inthe tube. An O-ring 784 is disposed between the lens carrier 780 and aspacer 790, the spacer 790 having a field stop 794 at its distal end. Aneyepiece lens 798 is disposed in engagement with the proximal end of thespacer 790. Each of the lenses 776, 798 according to this configurationare symmetrical; that is, each lens 776, 798 includes identically curved(convex) distal and proximal surfaces. Additionally and according to atleast one version, each of the peripheral edges of the lenses 776, 798can be raised to prevent damage, such as scratching to the opticalsurfaces.

A retaining cap 800 engageable with the proximal end of the tubularsection 770, the retaining cap 800 includes an open distal end 802 andengagement features, such as annular slots 806, as well as a proximalviewing opening. A plano window 804 is disposed between the eyepiecelens 798 and the rear wall of the retaining cap 800 wherein theretaining cap 800 can be twisted in order to apply a compressive forceagainst the resilient O-rings 784 to effect minor focus adjustments atthe factory level, for example, to compensate for manufacturingtolerances.

A thin sheet 810 of copper or other flexible metal can be positionedsuch that each end of the sheet 810 is secured beneath the extending earportions 738 and spans across the raised surface 756 of the secondsection 754. As discussed herein, this portion of the assembly is usedin connection with diopter wheel 840.

According to this version, the upper portion 720 of the housing 712includes a plurality of holes 744 that can be aligned with the posts 742of the lower portion 716 to enable the housing 712 to be secured.

Upon assembly, the optical assembly 710 can be attached to theillumination assembly 610 in which the lower portion 716 is includes apair of spaced rail sections 850 that can be engaged with the upperportion sidewalls 698, FIG. 8(a), of the assembly support member 628.

Referring to FIG. 8(e), the diopter wheel 840 is shown prior toattachment, along with a retention cap or hub 844. The diopter wheel 840includes a center through aperture 842 that is aligned with a lateralcavity 699 formed in the intermediate portion 637 of the assemblysupport member 628. The hub 844 is engageable with to extend through theaperture 842 and into the cavity 699 to retain the wheel 840, as shownin FIG. 8(f). In this embodiment, the outer periphery 846 of the diopterwheel 840 is caused to extend into the raised second section 754 of theviewing assembly 710 and into contact with the detent 764, which is heldin place by the thin metal sheet 810, acting as a biasing spring.

The illumination assembly 610 and optical assembly 710 according to thisinstrument design does not require fasteners, wherein all of thecomponents can be assembled based on a series of interconnecting fitsbetween the various components.

Referring to FIGS. 9(a)-10(b) and according to another embodiment, thepreceding illumination assembly can be used with an existing viewingassembly 610, as would be found, for example, in conjunction with theophthalmic instrument 200 of FIG. 2.

A partially assembled version is shown in FIGS. 9(b) and 9(c), whereinthe illumination assembly 610 is identical to that previously describedand further including a diopter wheel 840 that is attached to theassembly 610. For purposes of this discussion, similar parts are hereinlabeled with the same reference numerals for the sake of clarity. Theviewing assembly 910 is attached to the upper portion 637 of theillumination assembly 610, the viewing assembly 910 according to thisexemplary embodiment comprising a single component that includes a pairof engagement rails 918 to enable the viewing assembly 910 to slidinglyengage with the sidewalls 698, FIG. 8(a), of the upper section 637 ofthe assembly support member 628. The viewing assembly 910 according tothis embodiment includes a pair of upwardly extending ears 924, similarto those previously described along with a spring support section 928having a surface 932 disposed between the spaced ears 924. The surface932 includes a center opening 936 sized to receive a detent 940 in whichthe exterior of the surface of the support section 928 supports a thinmetallic sheet section 810 whose ends are disposed beneath the ears 924in order to engage the outer periphery 846 of the supported diopterwheel 840 when rotated. The single component is configured to permitviewing, including a groove disposed on the upper surface.

FIGS. 10(a) and 10(b) illustrate a fully assembled version of thislatter instrument 1000, including a cover 1020 having slots 1032 and1036 each sized to enable access to the diopter wheel 840 and aperturewheel 692, as well as a flexible eye cup 1028 at the distal end thereoffor contacting the patient.

Functionally, the overall effects provided by the creation of a virtualpupil for each instrument are schematically depicted in FIGS. 12 and 13,comparing the otoscopic and ophthalmic versions described herein withthe prior art versions depicted in FIGS. 1 and 2, respectively. With theherein described optical systems, the field of view can be increasedfrom about 5 degrees to about 15 degrees for each device and enables theentire tympanic membrane and a larger portion of the retina to be viewedall at once by the caregiver by an otoscope and ophthalmoscope,respectively.

Another illustration of the overall benefit of the herein describedinvention is shown comparatively with reference to FIG. 14 between aprior art instrument 1100 having a distance D1 between the eye of thepatient 1104 and that of the clinician 1108 and a field of view based onthis distance. In the instrument 1150 and creating a “virtual eye” 1158as previously described the field of view is significantly increasedbased on the shorter distance between the virtual eye 1158 and that ofthe patient 1104. The foregoing advantage is provided in spite of theoverall increase in thickness of the instrument 1150, in which thecreation of an entrance pupil (or “virtual eye”) reduces the effectiveworking distance between the eye of the caregiver and the patient bynegating the thickness of the instrument to permit the extended field ofview and using a direct ophthalmoscope.

PARTS LIST FOR FIGS. 1-14

-   100 instrument (otoscope)-   104 instrument head-   108 distal end, instrument head-   112 proximal end, instrument head-   115 hollow interior-   124 distal insertion portion-   126 slot-   128 distal opening-   130 magnifying optic or window-   132 bayonet connector-   200 instrument (ophthalmoscope)-   204 instrument head-   205 distal end-   207 proximal end-   214 bayonet connector-   220 diopter wheel-   226 aperture wheel-   228 sliding switch-   400 instrument-   404 instrument head-   406 distal end-   408 proximal end-   409 insufflation port-   411 illumination connector-   413 tip attachment and retention mechanism-   416 conical insertion portion-   419 actuator knob-   420 inner former-   423 lower portion-   427 opening-   428 cover-   430 optics assembly-   432 housing-   434 distal section, housing-   435 intermediate section, housing-   437 proximal section, housing-   439 distal opening-   441 proximal opening-   444 plano window-   447 objective lens-   449 relay lens-   451 field stop-   453 first spacer-   454 distal section-   456 proximal section-   457 intermediate section-   459 aperture, narrowed-   461 O-rings-   463 second spacer-   465 field stop-   467 peripheral grooves-   469 O-ring-   471 eyepiece lens-   473 retaining cap-   475 distal open end-   477 annular slots-   479 exterior engagement features-   480 image-   481 proximal viewing opening-   482 image plane-   483 entrance pupil-   540 optical module-   544 housing-   546 distal end opening-   548 proximal end opening-   600 instrument, medical diagnostic-   610 illumination assembly-   612 LED-   614 circuit board-   616 spacer-   618 through aperture, spacer-   620 lower flange-   622 O-ring-   624 curved light pipe-   625 slot-   626 bottom surface-   627 portion of light pipe-   628 assembly support member-   629 recess-   630 lower portion, assembly support member-   631 external notch-   634 aperture-   636 lens element-   637 upper portion, assembly support member-   638 slot-   639 intermediate portion, assembly support member-   642 projecting leg portions-   644 recess-   646 engagement rails-   650 illumination connector-   654 upper portion, illumination connector-   656 intermediate portion, illumination connector-   658 lower portion, illumination connector-   660 axial through opening-   664 insulator-   667 lower portion, insulator-   670 center conductor-   673 axial contacting end-   677 curved portions-   678 flats-   679 curved portions, assembly support member-   682 spring clip-   686 reticle wheel assembly-   688 upper engagement portion, wheel assembly-   690 lower engagement portion, wheel assembly-   692 aperture wheel-   696 through aperture-   698 sidewalls, upper portion-   699 cavity-   700 reticle lens-   704 prismatic member-   704A prismatic member-   706 receiving cavity-   710 optical or viewing assembly-   712 housing-   716 lower or bottom portion-   720 upper or top portion-   724 top surface-   728 semi-circular groove-   730 ears-   732 first lens-   734 vertical portion-   736 second lens-   738 transverse portion-   742 posts-   744 holes-   750 first portion-   754 second portion-   756 raised surface-   760 center slot-   764 detent-   766 third portion-   770 tubular portion-   776 relay lens-   780 lens carrier-   784 O-ring-   790 spacer-   794 field stop-   798 eyepiece lens-   800 retaining cap-   802 open distal end-   804 plano window-   806 annular slots, cap-   810 thin metal sheet-   840 diopter wheel-   842 center aperture-   844 hub-   846 outer periphery, diopter wheel-   850 spaced rail portions-   910 viewing assembly-   918 engagement rail portions-   924 ears-   928 support section-   932 surface-   936 center opening-   940 groove-   1000 instrument-   1020 cover-   1028 eye cup-   1032 slot, cover-   1100 instrument-   1104 patient eye-   1108 clinician eye-   1150 instrument-   1158 virtual eye

It will be apparent that other modifications and variations of theforegoing exemplary embodiments will be understood from the foregoingdescription as well as the following claims:

The invention claimed is:
 1. An ophthalmoscope configured for viewing ahuman eye, the ophthalmoscope comprising: a housing having a distal end,an opposing proximal end, and an interior; an optical system and anillumination system disposed within the interior of the housing, theoptical system comprising: a distal objective lens; an aperture stopproximal to the distal objective lens; and at least one relay lens, andeyepiece lens proximal to the aperture stop, each component of theoptical system being commonly disposed along an optical axis; theillumination system comprising: a source of illumination and a pluralityof optical components aligned along an illumination axis that isseparate from the optical axis and in which the optical system createsan entrance pupil external of the distal end of the instrument housingand proximal to the viewed eye of a subject, the entrance pupil beingspatially separated from an exit pupil located at the eye of the user inorder to create closer proximity and provide an increased field of viewof the target of interest.
 2. The ophthalmoscope according to claim 1,wherein the plurality of components of the illumination system areassembled in an interlocking manner relative to the housing.
 3. Theophthalmoscope according to claim 1, wherein the objective lens, atleast one relay lens and eyepiece lens each comprise opposing opticalsurfaces that are symmetrical to one another, enabling each of thesymmetrical optical elements to be assembled in opposing configurationswithout changing the optical effect thereof.
 4. The ophthalmoscopeaccording to claim 3, wherein each of the lenses include a raisedperipheral edge to protect the lenses from surface damage.
 5. Theophthalmoscope according to claim 1, wherein the lenses are manufacturedfrom plastic.
 6. The ophthalmoscope according to claim 1, including atleast one field stop.
 7. The ophthalmoscope according to claim 6,including at least one field stop for preventing glare.
 8. Theinstrument according to claim 3, wherein the optical system is disposedwithin a viewing assembly that is connected by interlocking with theillumination assembly.
 9. A plurality of medical diagnostic instruments,wherein each of the medical diagnostic instruments include an opticalsystem that is configured to produce a virtual entrance pupil formed ata distal end of the instrument and proximal to a medical target in orderto obtain closer proximity relative to a target relative to an exitpupil at the eye of the user and so as to increase the field of view andin which at least one of the plurality of instruments is anophthalmoscope.
 10. The plurality of medical diagnostic instrumentsaccording to claim 9, wherein the plurality of instruments includes anotoscope and an ophthalmoscope.
 11. The plurality of medical diagnosticinstruments according to claim 9, in which the optical system isintegrated within at least one instrument housing.
 12. The plurality ofmedical diagnostic instruments according to claim 9, further comprisinga module that is releasably attached to at least one of the medicaldiagnostic instruments.
 13. The plurality of medical diagnosticinstruments according to claim 9, in which the optical system comprisesan objective distal lens, at least one relay lens and a proximaleyepiece lens, each commonly disposed along an optical axis of theinstrument.
 14. The plurality of medical diagnostic instrumentsaccording to claim 13, wherein each of the lenses of the optical systemcomprise symmetric optical surfaces.
 15. The plurality of medicaldiagnostic instruments according to claim 14, in which the lenses arereversible.
 16. The plurality of medical diagnostic instrumentsaccording to claim 9, in which at least one of the instruments furthercomprises an illumination assembly and in which the optical system andthe illumination assembly include features to enable an interlockingconnection therebetween.
 17. The plurality of medical diagnosticinstruments according to claim 16, wherein the illumination assemblyincludes a plurality of components each having features to enable aninterlocking connection therebetween.
 18. The plurality of medicaldiagnostic instruments according to claim 14, in which each of thereversible lenses is made from plastic.
 19. The plurality of medicaldiagnostic instruments according to claim 18, in which each of thereversible lenses include a raised peripheral edge on each of theoptical surfaces thereof.
 20. An optical module for placement within amedical diagnostic instrument to increase the effective field of viewwith respect to a target of interest, the instrument including aninstrument head having an interior, the optical module comprising: amodule housing sized to be fitted within the interior of the instrumenthead; and an optical system disposed within the module housing, theoptical system including least one distal optical element, an aperturestop, at least one pair of relay lenses and an imaging lens disposedwithin an interior of the module housing and aligned commonly along anoptical axis, and wherein the optical system forms an entrance pupildistal of the distal end of the module but proximal of the target ofinterest in order to decrease the working distance of the medicaldiagnostic instrument relative to an exit pupil at the eye of the user,thereby increasing the effective field of view of the target.